What is the Difference Between Pemphigoid and Pemphigus?

Pemphigus and pemphigoid are both rare autoimmune blistering diseases that affect the skin and/or mucous membranes. They are caused by the immune system malfunctioning and creating antibodies that attack normal body structures, leading to blisters. However, there are differences between the two conditions:

1. Affected layer of the skin: Pemphigus affects the outer layer of the skin (epidermis), causing shallow ulcers or fragile blisters that break open quickly. Pemphigoid affects a lower layer of the skin, between the epidermis and the dermis, creating tense blisters that do not break easily.
2. Type of blisters: Pemphigus is characterized by shallow ulcers or fragile blisters that break open quickly. Pemphigoid presents with stronger or "tense" blisters that don't open easily. Those with pemphigoid are also more likely to have hot, red, and itchy hive spots.
3. Causes: The causes of pemphigus and pemphigoid are not well understood, but they are thought to be related to genetic predisposition and differences in immune responses.
4. Symptoms: Symptoms of these diseases can include pain in the mouth, bleeding when brushing teeth, recurrent bloody noses, red eyes, pain while urinating or with bowel movements, or tenderness during intercourse, depending on where the blisters are located.
5. Diagnosis: Pemphigus and pemphigoid are diagnosed through special testing and clinical presentation. Types of testing include lesion biopsy and direct immunofluorescence.
6. Treatment: Treatment for both pemphigus and pemphigoid often involves systemic corticosteroids, such as prednisone, combined with adjuvant immunosuppressants like azathioprine, mycophenolate mofetil, or the anti-CD20 monoclonal antibody rituximab.

Comparative Table: Pemphigoid vs Pemphigus

Here is a table highlighting the differences between pemphigoid and pemphigus:

Pemphigoid, specifically bullous pemphigoid (BP), is a chronic autoimmune disorder with blistering that predominantly affects the skin and sometimes the mucosa. In contrast, pemphigus is characterized by intraepidermal blistering and can present in several forms, such as pemphigus vulgaris and pemphigus foliaceus. Diagnosis for both conditions is based on clinical manifestations, histopathology, and immunodiagnostic tests.